Large tanks are currently provided for storing and dispensing fluids, such as fracturing liquids, drilling muds, and the like, for use at an oil or gas well site. Such tanks are also used to receive and hold fluids and chemicals at industrial plants. They are also used on environmental clean-up jobs, as well as spills, to hold fluids until they can be properly disposed of. When empty, these tanks are towed by truck from one site to another, where they are refilled and reused. The tanks usually have lengths of 30 to 40 feet, a height of from approximately 9 to 12 feet, and a width of 8 feet. Various federal, state and local highway ordinances limit the size of these trailers for over-the-road transport. These tanks are constructed to have a large capacity, holding thousands of gallons of liquid; therefore, there is a need to provide a mobile storage tank constructed and arranged to not only increase the storage capacity of the tank for holding fluids at the job site, but also dimensioned to conform to the highway ordinances for over-the-road transport.